There is a type of conventional image forming apparatus, such as a printer or a multi-function peripheral, which has a so-called network print function and performs a printing process (image forming process) in response to a print request (image formation request) from each of terminals which are connected over a network. By making use of the network print function, a single image forming apparatus can advantageously be shared by a plurality of terminals.
In general, this type of image forming apparatus, however, spools print requests from the terminals in a job storage as print jobs (image formation jobs), and performs printing processes for the print jobs in the order of reception. Thus, if a terminal user has delayed in going for a printed matter that is a print result, it is possible that the printed matter is taken away by a third person. In addition, it is difficult to ensure the confidentiality of the printed matter.
To cope with this problem, there is known a conventional image forming apparatus which includes a user detector for detecting user information of an approaching user and a function of preferentially executing, when the user information of the approaching user is detected by the detector, a job with respect to which the same user information as the user information of the approaching user is set. By using this function, the approaching user can collect a newly output printed matter as his/her own printed matter (see, for instance, Jpn. Pat. Appln. KOKAI Publication No. 2007-098590).
However, the conventional image forming apparatus having the function of preferentially executing the job of the approaching user has the following technical problem that has to be solved. Specifically, in a case where there are users approaching to the image forming apparatus, the conventional function executes jobs in the order of detection by the user detector. In this case, even if no significant difference is present between the timings that the users have approached the image forming apparatus, the elapsed time from the issuance of a print request from the terminal differs for each user.
In general, a user, who has instructed the output of a printed matter with urgency (which may include confidentiality), immediately approaches the image forming apparatus after a print request, and confirms the printed matter. On the other hand, most of users, who have instructed the output of printed matters without urgency, do not immediately go for them after print requests. However, if a user X, who immediately comes for a printed matter, and a user Y who, after a while, comes for a printed matter, approach the image forming apparatus together, and if the user information of the user Y is first detected, the printed matter of the user Y is first output, and the user X has to wait until the printed matter of the user Y is printed out.